Drinks that keep people awake for people with bad stomachs? -details inside-?

Hi, i am 24 years old and i do have the following stomach problems:

Acid reflux (GERDS)

IBS (irritable bowel syndrome)

Gastritis

Some lactose intolerance (it's getting better now)

Before i had these problems (got sick at age 20), to stay up or basically wake up i would drink my morning coffee or latte, but since 2007, obviously i had to cut everything off, and change my diet. However, i am finally able to go back to school, but i do work overnights, my problem is most of my classes for my major they are in the evening and i was to take 5 classes per semester so i can get my BA in understand 2 years.

I notice the only beverage i can drink with out giving me a serious case of "the runs" is starbucks frappicuino (sp?) cold coffee in the glass bottle you can buy from any store, but the problem is, it does keep me wide awake for work which is great but i do end on with going to the bathroom more which isn't good for my type of work.

So my question is there a drink out there for me that can not have me falling asleep at work so i can add another class to my schedule?

Thank you very much.